Systems, methods and devices for ablation, crossing, and cutting of occlusions

ABSTRACT

Ablation, crossing, and cutting systems, devices and associated methods, including a crossing device, comprising, in combination: a spring-enhanced handle and body configured to controllably extend and retract a blade within a microcatheter for addressing an occlusion within a vessel of a patient to provide improved access for supplemental treatment and reperfusion.

RELATED APPLICATION

This application claims the full Paris Convention benefit of andpriority to U.S. Provisional Patent Application Ser. No. 61/239,321,filed Sep. 2, 2009; and PCT Application Ser. No. PCT/US09/55950, filedon Sep. 3, 2009; the contents of which are incorporated by referenceherein in their entirety, as if fully set forth herein.

BACKGROUND Field

This disclosure relates to systems and apparatus for treating humans viaallopathic or surgical intervention, minimally invasive surgicalpractices, endovascular procedures, percutaneous procedures, and relatedmedical procedures. Specifically, this disclosure relates to systems foraddressing vessel lumen-based issues and treatment of occlusions withina body, including those related to peripheral vascular disease states,cardiovascular diseases, cerebrovascular diseases, and others.

SUMMARY

Improved ablation, crossing, and cutting devices and associated systemsand methods are disclosed for treatment of occlusions within a body,owing to the paucity of effective devices available clinically, and thelongstanding needs in this field of art.

According to embodiments, a crossing device is disclosed, comprising, incombination: a body coupled to a microcatheter at a proximal end of themicrocatheter; a handle coupled to a blade at a proximal end of theblade, the blade disposed within a lumen of the microcatheter; wherein asharpened tip of the blade is configured to advance from a naturalposition within the lumen of the microcatheter to an extended positionbeyond a distal end of the microcatheter as the handle is advancedrelative to the body.

The crossing device may further comprise a spring configured to compressas the handle is advanced relative to the body; wherein the spring isconfigured to expand and retract the blade relative to the microcatheteras the handle is released.

The crossing device may further comprise a luer configured to attach toa proximal end of the handle and provide adaptable use of a supplementaltreatment device in combination with the crossing device. The luer maybe configured to guide a supplemental treatment device to the lumen ofthe microcatheter or a lumen of the blade. The supplemental treatmentdevice may be at least one of: a guidewire, a PTA balloon, and a stentdevice.

The tip of the blade may be disposed at a distal end of the blade and isof a rigid material. The tip of the blade may be a hollow, sharpened,everted tip.

The handle and the body may be configured to limit the expansion of thespring and provide the natural position of the blade and furtherconfigured to selectively lock the blade in at least one of the naturalposition and the extended position. The body may further comprise a nosedetachable from the body and secured to the microcatheter, such that themicrocatheter is selectively removable from the body.

According to embodiments, an improved surgical method for addressingblockage within a vessel is disclosed, comprising, in combination:delivering an apparatus including at least a microcatheter to a desiredtreatment situs; positioning the microcatheter having at least a bladeproximate to a surface of an occlusion, wherein the microcatheter isattached to a body and comprises a lumen; providing the blade within thelumen of the microcatheter to the surface of the occlusion, wherein theblade is attached to a handle; advancing the blade to an extendedposition by manipulation of the handle relative to the body; andretracting the blade to a natural position by releasing the handle.

The blade may be retracted by a spring between the handle and the body.The method may result in reconfiguration of at least a portion of theocclusion, whereby a different flow condition may be achieved.

The method may further comprise advancing the microcatheter and theblade through a channel created by advancement of the blade to anextended position. The method may further comprise providing asupplemental treatment device to the occlusion through a lumen of theblade. The supplemental treatment device may be at least one of aguidewire, a PTA balloon, and a stent device.

According to embodiments, a kit is disclosed, comprising: a crossingdevice further comprising: a body coupled to a microcatheter at aproximal end of the microcatheter; a handle coupled to a blade at aproximal end of the blade, the blade disposed within a lumen of themicrocatheter; wherein a sharpened tip of the blade may be configured toadvance from a natural position within the lumen of the microcatheter toan extended position beyond a distal end of the microcatheter as thehandle is advanced relative to the body; and directions for use.

The kit may further comprise a supplemental treatment device configuredto be advanced within the lumen of the microcatheter. The kit mayfurther comprise a luer disposed at a proximal end of the handle andconfigured to guide the supplemental treatment device into the lumen ofthe microcatheter. The supplemental treatment device may be at least oneof: a guidewire, a PTA balloon, and a stent device.

A system for addressing obstructions within lumens, comprising, incombination: a body coupled to a microcatheter at a proximal end of themicrocatheter; a handle coupled to a blade at a proximal end of theblade, the blade disposed within a lumen of the microcatheter; a luerconfigured to attach to a proximal end of the handle and provideadaptable use of a supplemental treatment device in combination with thecrossing device; a spring configured to compress as the handle isadvanced relative to the body; wherein a tip of the blade may beconfigured to advance from a natural position within the lumen of themicrocatheter to an extended position beyond a distal end of themicrocatheter as the handle is advanced relative to the body; whereinthe spring may be configured to expand and retract the blade relative tothe microcatheter as the handle is released.

DRAWINGS

The above-mentioned features and objects of the present disclosure willbecome more apparent with reference to the following description takenin conjunction with the accompanying drawings wherein like referencenumerals denote like elements and in which:

FIG. 1A is a schematic view of an embodiment of a crossing device in anatural position, according to embodiments of the present disclosure;

FIG. 1B is a schematic view of an embodiment of a crossing device in anextended position, according to embodiments of the present disclosure;

FIG. 2A is a schematic view of an embodiment of a crossing device in anatural position, according to embodiments of the present disclosure;

FIG. 2B is a schematic view of an embodiment of a crossing device in anextended position, according to embodiments of the present disclosure;

FIG. 3 is an exploded view of an embodiment of a crossing device,according to embodiments of the present disclosure;

FIG. 4 is a cross-sectional view of an embodiment of a crossing device,according to embodiments of the present disclosure;

FIG. 5A is a schematic view of an embodiment of a blade of a crossingdevice, according to embodiments of the present disclosure; and

FIG. 5B is a schematic view of an embodiment of a blade of a crossingdevice, according to embodiments of the present disclosure.

DETAILED DESCRIPTION

The present inventors have discovered that treatment of conditions,including chronic total occlusions, remain challenged by the paucity ofextent devices. Namely, surgeons require improved apparatus to impact,address, and ameliorate occlusions by thrombi, emboli, and otherobstructions in real time during procedures.

In the following detailed description of embodiments of the presentdisclosure, reference is made to the accompanying drawings in which likereferences indicate similar elements, and in which is shown by way ofillustration specific embodiments in which the present disclosure may bepracticed. These embodiments are described in sufficient detail toenable those skilled in the art to practice the present disclosure, andit is to be understood that other embodiments may be utilized and thatlogical, mechanical, electrical, functional, and other changes may bemade without departing from the scope of the present disclosure. Thefollowing detailed description is, therefore, not to be taken in alimiting sense, and the scope of the present disclosure is defined onlyby the appended claims. As used in the present disclosure, the term “or”shall be understood to be defined as a logical disjunction and shall notindicate an exclusive disjunction unless expressly indicated as such ornotated as “xor.”

The inventors of the present disclosure have invented and reduced topractice improved systems, comprised of devices and methods forablating, crossing, or cutting an occlusion including known constraintsof managing fluid-flow and other access issues within a body,particularly in the lumen of vessels. The devices and methods discussedherein may be employed for medical treatment and in conjunction withother devices and methods for medical treatment, as known to thoseskilled in the art.

Where a patient is indicated for certain treatment, monitoring, orintervention or suffers from a disease, a lumen of a blood vessel orother fluid-bearing vessel may become occluded. For example, a chronictotal occlusion (“CTO”) or other partial or total obstruction of a bloodvessel may occur or be the result of a thrombus, an embolism,atherosclerosis, or other disease that results in a blockage,restriction, or occlusion of fluid flow within a body. Often, duringprocedures, situations arise requiring immediate intervention, such asto address a CTO.

Where treatment of an occlusion by endovascular procedure is desired,medical professionals may attempt endovascular surgical procedures.Endovascular procedures include angioplasty procedures, stent placement,various scope procedures, and plethoric diagnostic, intermediary andinterlocutory clot addressing schemes, which may include temporarily orpermanently emplaced devices.

An occlusion may include a fibrous cap, composed of lipids, endothelialcells, macrophages, smooth muscle cells, foam cells, connective tissue,and other vascular materials. An occlusion may include calcification,such that the occlusion becomes hardened. Under these conditions,various endovascular procedures including thrombectomy, angioplasty,stent placement, retrieval of an obstruction, and others may becomplicated or prevented by the difficulty or inability to penetrate theocclusion. For example, such procedures may require at least partialpenetration of an occlusion before the procedure may be commenced orcompleted. Often, establishing some degree of reperfusion is critical.

According to embodiments, as shown in FIGS. 1A, 1B, 2A, and 2B, crossingdevice 1 may include body 13, microcatheter 21, handle 12, and blade 16.According to embodiments, crossing device 1 allows for a handheldmechanical penetration of an occlusion. Surgeons and interventionalistshave expressed ongoing needs for devices leveraging their “hand” or feelfor manipulating devices in situ.

According to embodiments, body 13 may be attached to microcatheter 21,and handle 12 may be attached to blade 16, such that handle 12 ismoveable relative to body 13, and movement of handle 12 relative to body13 causes advancement and retraction of blade 16 along the inner portionof microcatheter 21. FIGS. 1A and 2A show crossing device 1 in a naturalposition, with handle 12 and blade 16 retracted; FIGS. 1B and 2B showcrossing device 1 in an extended position, with handle 12 and blade 16extended.

According to embodiments, handle 12 may include or be combined with oneor more of luer 11, plunger rod 14, hypo support 15, and blade 16. Forexample, as shown in FIGS. 3 and 4, handle 12, luer 11, plunger rod 14,hypo support 15, and blade 16 may be combined to form an integratedunit. One or more interfaces (e.g., threading, etc.) or fixations (e.g.,adhesive, epoxy, etc.) may be provided to combine said components.

According to embodiments, body 13 may include or be combined with one ormore of nose guide 19, nose 18, heat shrink 20, and microcatheter 21.For example, as shown in FIGS. 3 and 4, body 13, nose guide 19, nose 18,heat shrink 20, and microcatheter 21 may be combined to form anintegrated unit. One or more interfaces (e.g., threading, etc.) orfixations (e.g., adhesive, epoxy, etc.) may be provided to combine saidcomponents.

According to embodiments, spring 17 may be disposed between at least aportion of handle 12 and at least a portion of body 13. For example, asshown in FIG. 4, spring 17 extends between plunger rod 14—which isattached to handle 12—and nose guide 19—which is attached to body 13.

According to embodiments, spring 17 may tend to separate handle 12 frombody 13 by way of elastic expansion. Handle 12 and body 13 may beconfigured to set a limit on the separation. For example, as shown inFIGS. 3 and 4, plunger rod 14 may include a flange that contacts aportion of body 13 to prevent travel along the axis beyond a certainpoint.

According to embodiments, nose 18 may be separate from and attachable tonose guide 19. Nose 18 may be fixably attached to microcatheter 21 andremovably attached to nose guide 19, such that a microcatheter may beexchanged by removing nose 18. Such an option avoids the need to replacean entire system for need of a new microcatheter.

According to embodiments, crossing device 1 may facilitate use of aguidewire. Blade 16 may be configured with a hollow inner portion toallow a guidewire to be advanced from a proximal end of blade 16 to adistal end of blade 16. A guidewire lumen within blade 16 may beconfigured to accommodate any guidewire used for general vascularsurgical procedures, such that a separate or distinct guidewire is notrequired for operation of crossing device 1. Such technology is known inthe art, and incorporated herein by reference are the following U.S.patent applications and publications: U.S. Pat. No. 6,066,149, U.S. Pat.No. 5,972,019, U.S. Pat. No. 5,695,469, U.S. Pat. No. 6,506,178, U.S.Pat. No. 6,533,753, U.S. Pat. No. 6,579,302, U.S. Pat. No. 6,663,577,U.S. Pat. No. 7,399,291, U.S. Pat. No. 5,879,305, U.S. Pat. No.5,724,977, U.S. Pat. No. 5,596,990, U.S. Publication No. 2004/0230219,U.S. Publication No. 2005/0209559, U.S. Publication No. 2007/0265563,U.S. Publication No. 2005/0049574, U.S. Publication No. 2006/0184186,U.S. Publication No. 2001/0031981, U.S. Publication No. 2007/0208368,U.S. Publication No. 2007/0021685, U.S. Publication No. 2008/0097247,U.S. Publication No. 2008/0140101, U.S. Publication No. 2008/0114390,U.S. Publication No. 2008/0228171, and U.S. Publication No.2008/0249465.

According to embodiments, a luer 11 may be configured to interface withhandle 12, as shown in FIGS. 3 and 4. Luer 11 may be a detachablehub/luer device configured to direct devices to microcatheter 21. Luer11 may facilitate use of a support catheter, PTA balloon catheter,guidewire, or another lumen-configured or catheter-based supplementaltreatment device to be exchanged with components of crossing device 1during use, without removal of crossing device 1 from a patient. Such aconfiguration provides the ability to operate crossing device 1 intandem or in sequence with other devices intended to deliver treatmentto the same or nearby location.

According to embodiments, devices advanced within the lumen of blade 16or otherwise provided through luer 11 may be operated, manipulated, andmoved either along with or independent of handle 12, body 13, or theirassociated attached components.

According to embodiments, blade 16 may be configured to penetrate anocclusion upon contact with the occlusion. The distal end of blade 16may include one of a variety of shapes to facilitate addressing theocclusion. Examples are shown in FIGS. 5A and 5B. For example, blade 16may include an everted end, an end with a sharpened tip, a concave end,a convex end, a coring tip, or other geometry to address an occlusion.Blade 16 may be hollow or solid.

According to embodiments, microcatheter 21 and blade 16 may providesufficient flexibility to provide trackability within vessels of apatient. Microcatheter 21 and blade 16 may also provided sufficientrigidity to adequately transfer translational and rotational forces tobe responsive at a distal end to a user located at a proximal end.According to embodiments, a tip at a distal end section of blade 16 maybe relatively rigid, to provide a force of impact to an occlusion uponextension of the same.

According to embodiments, blade 16 may be configured to providerotational motion at the point of deployment (e.g., at or near thedistal end of crossing device 1). For example, as a user provides torqueto handle 12, the torque may be translated along blade 16 to the distalend of blade 16. A torque provided at the distal end may improvetreatment of the occlusion. The torque may be applied and translatedbefore, during, or after extension of blade 16 beyond the distal end ofmicrocatheter 21 and penetration of the occlusion.

According to embodiments, blade 16 may be configured to automaticallyrotate as it advances longitudinally relative to microcatheter 21. Forexample, threading may be provided about the axis along which blade 16travels, such that travel of blade 16 along the axis also results inrotation of blade 16. For example, microcatheter 21 may be provided onat least a portion of its inner surface with threading, channels, orother guiding members 40 to govern the manner in which blade 16 isadvanced and retracted therein. Blade 16 may be provided with threadingor other features to complement the guiding members of the axis alongwhich blade 16 travels. For example, at least a portion of blade 16 mayhave a substantially spiral geometry adapted to interface with acomplementary threading of microcatheter 21.

According to embodiments, blade 16 may be configured to penetrate orcross a section of an occlusion. According to embodiments, at least aportion of the occlusion may be captured or enclosed by features ofblade 16. For example, ridges, protrusions, edges, and spiral geometriesmay be provided at the distal end of blade 16 to capture or enclose atleast a portion of the occlusion that is penetrated by blade 16.Subsequently, blade 16 may be retracted, whereby at least a portion ofthe occlusion is removed by blade 16.

For example, where blade 16 includes a substantially spiral geometry,blade 16 may be advanced relative to microcatheter 21 with simultaneouslongitudinal and rotational motion, whereby the spiral geometry capturesat least a portion of the occlusion. Subsequently, blade 16 may beretracted longitudinally, whereby the portions of the occlusion aremaintained within the spiral geometry. For example, blade 16 may beretracted with microcatheter 21. The foregoing may result in a pathwithin the occlusion which may be the object of further operations, suchas by the same device or others, or may be a path that at leastpartially restores a flow of blood and reperfusion through theocclusion.

According to embodiments, blade 16 may be configured to be entirely oralmost entirely disposed within microcatheter 21 at its distal end whencrossing device 1 is in a natural position, as shown in FIGS. 1A and 2A,and to be somewhat extended beyond the distal end of microcatheter 21when crossing device 1 is in an extended position, as shown in FIGS. 1Band 2B.

According to embodiments, blade 16 may be configured to lock relative tomicrocatheter 21 when in a natural position or an extended position.Mechanisms to selectively or automatically lock and unlock blade 16 maybe provided and may be operable by a user located at a proximal end ofcrossing device 1 to activate or deactivate said mechanisms.

According to embodiments, crossing device 1 may be configured as eitheran “over the wire” device (see FIG. 4) or a “rapid exchange” device (notshown). For example, supplemental devices may be configured to interfacewith crossing device 1 in a rapid exchange configuration. Crossingdevice 1 may include at least one lumen to accommodate a supplementaldevice to be used in conjunction with other components of crossingdevice 1. For example, a rapid exchange lumen may entry access at ornear a proximal end of crossing device 1 and may extend to the distalend of crossing device 1 (e.g., the distal end of microcatheter 21).

According to embodiments, crossing device 1 may be used to address anocclusion. The distal end of crossing device 1, including a portion ofmicrocatheter 21, blade 16, or a guidewire, may be brought to thelocation of an occlusion. For example, the guidewire may first bebrought to the occlusion, followed by microcatheter 21 and blade 16.Blade 16 may be extended beyond the distal end of microcatheter 21 byoperation of handle 12, as disclosed herein. As the occlusion ispenetrated, increased advancement of microcatheter 21, blade 16, or aguidewire may be provided. Increased advancement of microcatheter 21,blade 16, or a guidewire may provide a improved position of the same tocontinue the crossing procedure in iterative steps. The process may berepeated in successive steps until the occlusion is crossed as desired.

According to embodiments, a method for causing blade 16 to penetrate anocclusion is disclosed. According to embodiments, microcatheter 21 maybe brought to an occlusion, such as a heavily calcified lesion or otherobstruction, as discussed herein. Blade 16 may be advanced by crossingdevice 1 such that it penetrates the occlusion. Blade 16 may retractwhen handle 12 is released, by the function of spring 17.

According to embodiments, the above described steps may be repeated asdesired. For example, the above described steps may be repeated untilthe occlusion is entirely breached or until sufficient access isprovided for other devices to act upon the occlusion. For example, a PTAballoon, stent device, or other catheter-based supplemental treatmentdevice may operate within a channel created by operation of crossingdevice 1.

According to embodiments, the method and use of crossing device 1 mayprovide increased perfusion of fluid flow through the channel created bycrossing device 1. The increased perfusion may provide improvedconditions to facilitate breakdown of the occlusion, such that perfusionalone or in combination with other methods may remove threats presentedby the occlusion.

According to embodiments, variations on embodiments may be made toprovide customizable use and performance characteristics of crossingdevice 1. For example, spring 17 may be omitted such that handle 12 maytravel relative to body 13 along the axis within certain limitations,such that the user may selectively and manually advance and retractblade 16 relative to microcatheter 21.

According to embodiments, crossing device 1 may be configured to allowblade 16 to be extended in a natural position and retracted based onaction taken by a user (not shown). The configuration shown in FIG. 4may be modified such that spring 17 is located such that its tendencytoward elastic expansion causes handle 12 to be advanced toward body 13.In such a configuration, retraction of handle 12 may compress spring 17,such that release of handle 12 causes advancement of blade 16 toward orbeyond the distal end of microcatheter 21.

According to embodiments, crossing device 1 may include two springs toprovide novel use and performance characteristics (not shown). Forexample, one spring may tend toward extension of blade 16, and anotherspring may tend toward retraction of blade 16. Blade 16 may beconfigured such that the distal tip of blade 16 is in a desired locationwhen equilibrium between the two springs is achieved in a naturalposition. A user may selectively advance or retract blade 16 byoperation of handle 12, and release for blade 16 to allow release of anyenergy stored in the springs, with the blade 16 eventually reachingequilibrium in a natural position.

According to embodiments, a kit of parts is disclosed. One or more kitsof parts can be envisioned by the person skilled in the art, the kits ofparts including at least one component disclose herein and configured toperform at least one of the methods herein disclosed. Likewise,directions for use (“DFU”) are included and the device may be part of asurgical tray or other packaged accessory set for surgeries. The kit maybe a sub-component of a surgical tray.

While the method and agent have been described in terms of what arepresently considered to be the most practical and preferred embodiments,it is to be understood that the disclosure need not be limited to thedisclosed embodiments. It is intended to cover various modifications andsimilar arrangements included within the spirit and scope of the claims,the scope of which should be accorded the broadest interpretation so asto encompass all such modifications and similar structures. The presentdisclosure includes any and all embodiments of the following claims.

It should also be understood that a variety of changes may be madewithout departing from the essence of the invention. Such changes arealso implicitly included in the description. They still fall within thescope of this invention. It should be understood that this disclosure isintended to yield a patent covering numerous aspects of the inventionboth independently and as an overall system and in both method andapparatus modes.

Further, each of the various elements of the invention and claims mayalso be achieved in a variety of manners. This disclosure should beunderstood to encompass each such variation, be it a variation of anembodiment of any apparatus embodiment, a method or process embodiment,or even merely a variation of any element of these.

Particularly, it should be understood that as the disclosure relates toelements of the invention, the words for each element may be expressedby equivalent apparatus terms or method terms—even if only the functionor result is the same.

Such equivalent, broader, or even more generic terms should beconsidered to be encompassed in the description of each element oraction. Such terms can be substituted where desired to make explicit theimplicitly broad coverage to which this invention is entitled.

It should be understood that all actions may be expressed as a means fortaking that action or as an element which causes that action.

Similarly, each physical element disclosed should be understood toencompass a disclosure of the action which that physical elementfacilitates.

Any patents, publications, or other references mentioned in thisapplication for patent are hereby incorporated by reference. Inaddition, as to each term used it should be understood that unless itsutilization in this application is inconsistent with suchinterpretation, common dictionary definitions should be understood asincorporated for each term and all definitions, alternative terms, andsynonyms such as contained in at least one of a standard technicaldictionary recognized by artisans and the Random House Webster'sUnabridged Dictionary, latest edition are hereby incorporated byreference.

Finally, all referenced listed in the Information Disclosure Statementor other information statement filed with the application are herebyappended and hereby incorporated by reference; however, as to each ofthe above, to the extent that such information or statementsincorporated by reference might be considered inconsistent with thepatenting of this/these invention(s), such statements are expressly notto be considered as made by the applicant(s).

In this regard it should be understood that for practical reasons and soas to avoid adding potentially hundreds of claims, the applicant haspresented claims with initial dependencies only.

Support should be understood to exist to the degree required under newmatter laws—including but not limited to United States Patent Law 35 USC132 or other such laws—to permit the addition of any of the variousdependencies or other elements presented under one independent claim orconcept as dependencies or elements under any other independent claim orconcept.

To the extent that insubstantial substitutes are made, to the extentthat the applicant did not in fact draft any claim so as to literallyencompass any particular embodiment, and to the extent otherwiseapplicable, the applicant should not be understood to have in any wayintended to or actually relinquished such coverage as the applicantsimply may not have been able to anticipate all eventualities; oneskilled in the art, should not be reasonably expected to have drafted aclaim that would have literally encompassed such alternativeembodiments.

Further, the use of the transitional phrase “comprising” is used tomaintain the “open-end” claims herein, according to traditional claiminterpretation. Thus, unless the context requires otherwise, it shouldbe understood that the term “compromise” or variations such as“comprises” or “comprising”, are intended to imply the inclusion of astated element or step or group of elements or steps but not theexclusion of any other element or step or group of elements or steps.

Such terms should be interpreted in their most expansive forms so as toafford the applicant the broadest coverage legally permissible.

The invention claimed is:
 1. A crossing device, comprising: a bodycoupled to a microcatheter at a proximal end of the microcatheter; aplunger rod, wherein the body defines a proximal recess into which aportion of a plunger is slidably received; a handle affixed to a cuttingblade at a proximal end of the blade, wherein the cutting blade has agenerally constant diameter along its length and comprises a sharpenedcutting surface defined by a beveled tip at a distalmost end of thecutting blade, wherein the cutting blade is disposed within a lumen ofthe microcatheter, and the microcatheter and cutting blade are flexibleto provide trackability within vessels of a patient, and wherein thecutting blade is sized and shaped to receive a guidewire forintravascular delivery to a target treatment site within a blood vesselof the patient, and further wherein the cutting blade is configured tomove axially and rotationally relative to the microcatheter; a spring,wherein the spring is configured to compress to advance the sharpenedcutting surface of the cutting blade axially outward from a naturalposition within the lumen of the microcatheter to an extended positionbeyond a distal end of the microcatheter as the handle is advanceddistally relative to the body, and wherein the spring is configured toexpand to axially retract the cutting blade from the extended positiontoward the natural position within the lumen of the microcatheter as thehandle is moved proximally; and a luer configured to be attached to aproximal end of the handle, wherein the luer is configured to facilitateuse of a supplemental treatment device in combination with the crossingdevice, wherein the body, handle, plunger rod, cutting blade,microcatheter, spring, and luer comprise an integrated unit adapted toremain together throughout operation of the crossing device within thepatient.
 2. The crossing device of claim 1 wherein the luer isconfigured to guide a supplemental treatment device to the lumen of themicrocatheter.
 3. The crossing device of claim 1 wherein the luer isconfigured to guide a supplemental treatment device to a lumen of thecutting blade.
 4. The crossing device of claim 1 wherein thesupplemental treatment device comprises at least one of the following: aguidewire, a PTA balloon, and a stent device.
 5. The crossing device ofclaim 1 wherein the tip of the cutting blade comprises a rigid material.6. The crossing device of claim 1 wherein the tip of the cutting bladecomprises a hollow, sharpened, everted tip.
 7. The crossing device ofclaim 1 wherein the handle and the body are configured to limit theexpansion of the spring and provide the natural position of the cuttingblade, and wherein the handle is further configured to selectively lockthe cutting blade in at least one of the natural position and theextended position.
 8. The crossing device of claim 1 wherein the body ofthe crossing device further comprises a nose detachable from the bodyand releasably secured to the microcatheter, and wherein themicrocatheter is selectively removable from the body.
 9. The crossingdevice of claim 1 wherein the lumen of the microcatheter furthercomprises guiding members configured to provide torque to the cuttingblade as the cutting blade is advanced from the natural position to theextended position.
 10. The crossing device of claim 1 wherein the tip ofthe cutting blade comprises a concave end.
 11. The crossing device ofclaim 1 wherein the tip of the cutting blade comprises a convex end. 12.The crossing device of claim 1 wherein the tip of the cutting bladecomprises a coring tip.
 13. The crossing device of claim 1 wherein thecrossing device is configured as a rapid exchange device.
 14. Thecrossing device of claim 1, further comprising a nose guide, a nose, anda heat shrink portion, and wherein the integrated unit further comprisesthe nose guide, nose, and heat shrink portion.
 15. The crossing deviceof claim 1 wherein the handle and body comprise a handle assembly, andwherein the spring is disposed between the handle and the body of thehandle assembly.
 16. The crossing device of claim 1 wherein the plungerrod is attached to the handle, and wherein the spring is integral withand extends between the plunger rod and a nose guide attached to thebody.
 17. A crossing device for treating an obstruction within a bloodvessel, the crossing device comprising: a flexible elongated shafthaving a proximal portion, a distal portion, and a lumen extendingtherethrough; a flexible cutting blade slidably disposed within thelumen of the flexible shaft and configured to move axially androtationally relative to the flexible shaft, wherein the cutting bladeis sized and shaped to receive a guidewire for intravascular delivery toa treatment site within the blood vessel at least proximate to theobstruction, and further wherein the cutting blade has a generallyconstant diameter along its length and comprises a sharpened cuttingsurface defined by a beveled tip at a distalmost end of the cuttingblade; and a handle assembly comprising a body, a handle, and a plungerrod therebetween, wherein a distal portion of the body is coupled to theproximal portion of the flexible shaft and a proximal portion of thehandle is connected to a proximal portion of the cutting blade, andwherein the body comprises a proximal recess into which a portion of theplunger rod is slidably disposed, and further wherein the handle isaxially and rotationally movable about the flexible shaft, wherein theproximal portion of the flexible shaft is contained within the body andthe proximal portion of the cutting blade is contained within thehandle, wherein during operation of the crossing device— axial movementof the handle in a distal direction advances the sharpened cuttingsurface of the cutting blade from a first natural position within thelumen of the flexible shaft to a second extended position beyond adistal end of the flexible shaft, and axial movement of the handle in aproximal direction retracts the cutting blade from its second extendedposition to its first natural position within the lumen of the flexibleshaft.